Synthesis and characterization of acetyloxypropylene dimethacrylate as a new dental monomer.

In this study acetyloxypropylene dimethacrylate was synthesized and proposed as an alternative monomer for triethyleneglycol dimethacrylate (TEGDMA) in dental mixtures. The monomer was prepared by the reaction of glycerol dimethacrylate with acetic anhydride. The exchange reaction was carried out in the presence of catalytic amounts of sulfuric acid. After purification the monomer was mixed with 2,2-dimethoxy-2-phenyloacetophenone and photo-irradiated. Unfilled homopolymer was evaluated for photopolymerization conversion and volumetric curing shrinkage. Water sorption, water solubility, flexural strength and hardness were measured. Also, dynamic mechanical studies were performed. For comparison TEGDMA was homopolymerized and its properties were evaluated. The proposed dimethacrylate has viscosity comparable to TEGDMA, lower curing shrinkage and lower degree of double bond conversion. After homopolymerization, its water sorption is much lower than that of homopolymerized TEGDMA. Concerning the mechanical properties, the homopolymerized acetyloxypropylene dimethacrylate has higher modulus and hardness than analogically cured TEGDMA. New dimethacrylate is a promising photocurable dental diluent owing to its low viscosity, good mechanical and water uptake properties.